CEO Perla Ni says the site is like Yelp. They don't rate the charities, users do.

"We think that the most useful information for donors at first glance is testimonials by people who live in that community and have used that non-profit's services or who have volunteered at that nonprofit and they can speak from their personal experience what that organization's impact is in that community."

GreatNonprofits.org doesn't screen the charities listed on the site. That's something you need to do on your own to find out where the money's going and how it's being used.